Panels of this description are useful, for example, in thermally insulating windows for buildings or vehicles, in solar collectors, in anti-glare vehicular windshields, or--when of limited width in relation to their length--as strips for shutters or blinds. They are generally formed with two spaced-apart glass panes at least one of which is coated on its inner face--confronting the other pane--with a layer of a material suitable for the intended purpose, e.g. as a reflector or absorber of infrared radiation or as a photoconductor; this material is usually applied by vapor deposition. The space separating the panes of such a compound glass panel may be filled with air or some other gas. It has also been proposed to insert a transparent foil of resinous material between these panes; in practice, however, the presence of this foil often gives rise to friction between it and the radiation-blocking layer on account of thermal expansion or contraction whereby that layer can be severly damaged. Also, imperfect contact between the foil and the layer produces voids or streaks impairing the light transmissivity of the panel.